The present invention relates to a liquid for contact lenses. More particularly, the present invention relates to a liquid for contact lenses, which can be preferably used for preservation, shipping, cleaning and disinfection of contact lenses.
In general, most of contact lenses, in particular, oxygen permeable hard contact lenses are prepared by using a silicone component. Accordingly, the lens surface becomes hydrophobic and wettability of the lens at initial wearing is poor. As a result, there easily occur that wearing sensation is lowered and sight cannot be sufficiently recovered.
Therefore, in order to keep surface wettability from production to wearing by users, the above oxygen permeable hard contact lens is preserved with wetting and shipped by subjection to surface treatment or immersion in a shipping solution such as physiological sodium chloride solution.
However, in the case that a contact lens is preserved with wetting and shipped in such physiological sodium chloride solution, base curve which is one of important standards of a contact lens sometimes varies.
Possibly, the above base curve of a contact lens varies during preservation of the contact lens by users.
For instance, bacteria may propagate in a preserving solution during preservation of a contact lens, or in a shipping solution during shipping of a contact lens. Accordingly, in order to prevent bacteria from propagating, an antiseptic is added to the preserving solution or the shipping solution.
However, antiseptic effect of the antiseptic is insufficient, or some of the antiseptics are poor in safety and durability. Accordingly, the antiseptic is not effective for preventing the propagation of bacteria.
In particular, in the case that a soft contact lens is immersed in the above preserving solution or the above shipping solution, which contains an antiseptic, the antiseptic sometimes adheres to the surface of the soft contact lens or is sometimes captured in the inside of the lens. Accordingly, it is desired that there is developed a method comprising using a polymerized antiseptic.
An object of the present invention is to provide a liquid for contact lenses, which can extremely decrease variation of base curve of a contact lens, in particular, an oxygen permeable hard contact lens during preservation and shipping, and which shows excellent antiseptic effect, excellent antibacterial effect and durability of these effects.
This and other objects of the present invention will become apparent from the description hereinafter.